When Edward Snowden met with reporters in a Hong Kong hotel room to spill the NSA’s secrets, he famously asked them to put their phones in the fridge to block any radio signals that might be used to activate the devices’ microphones or cameras silently.
Now Snowden’s attempting to build a solution that’s far more compact than a hotel mini-bar.
On Thursday at the MIT Media Lab, Snowden, and well-known hardware hacker Andrew “Bunnie” Huang plan to present designs for a case-like device that wires into your iPhone’s guts to monitor the electrical signals sent to its internal antennas.
The aim of that add-on, Huang and Snowden say, is to offer a constant check on whether your phone’s radios are transmitting.
Snowden and Huang are hoping to offer strong privacy guarantees to smartphone owners who need to shield their phones from government-funded adversaries with advanced hacking and surveillance capabilities-particularly reporters trying to carry their devices into hostile foreign countries without always revealing their locations.
“One real journalist in the right place at the right time can change history,” Snowden told the MIT Media Lab crowd via video stream.
“They’re overseas, in Syria or Iraq, and those have exploits that cause their phones to do things they don’t expect them to do,” Huang elaborated to WIRED in an interview ahead of the MIT presentation.
Huang’s and Snowden’s solution to that radio-snitching problem is to build a modification for the iPhone 6 that they describe as an “Introspection engine.” Their add-on would appear to be little more than an external battery case with a small mono-color screen.
Huang says it could even flip a “Kill Switch” to turn off the phone automatically.
“Our approach is: state-level adversaries are powerful, assume the phone is compromised,” Huang says.
Faraday bags can still leak radio information, Huang says, and smart malware can make an iPhone appear to be switched off when it’s not, as Snowden warned in an NBC interview in 2014.
Regardless, Huang says their intention was to allow reporters to disable a phone’s radio signals reliably while still using the device’s other functions, like taking notes and photographs or recording audio and video.
Snowden, who performed the work in his capacity as a director of the Freedom of the Press Foundation, adds that their goal isn’t merely just protection for journalists.
“You need to be able to increase the costs of getting caught,” Snowden said in a video call with WIRED following the presentation.
Huang and Snowden’s iPhone modification, for now, is little more than design.
To head off any potential mistrust of their Chinese manufacturers, Huang says the device’s code and hardware design will be fully open-source.
Huang, who lives in Singapore but travels monthly to meet with hardware manufacturers in Shenzhen, says that the skills to create and install their hardware add-on are commonplace in mainland China’s thriving iPhone repair and modification markets.
“This is something where, if you’re the New York Times, and you want to have a pool of four or five of these iPhones, and you have a few hundred extra dollars to spend on them, we could do that.” says Huang.
Snowden says he first met Huang after recommending him to television producers at Vice, who were looking for hardware hacking experts.
“He’s one of the hardware researchers I respect the most in the world,” Snowden says.
In late 2015, they began talking via the encrypted communications app Signal about Snowden’s idea of building an altered phone to protect journalists from advanced attacks that could compromise their location.
Huang says he’s tried to develop the most no-frills protection possible that still meets Snowden’s rightfully paranoid standards.
“If it wasn’t for the fact that Snowden is involved, I think this would seem pretty mundane,” Huang says almost bashfully.
